pc 26.2: attributes, 0-based sounds, vanilla loginPacket and loot - #1344

Replaces #1339, as asked in #1219. This is based on the current pc_26_2 (282f19b, with latest master) and contains only the 26.2 changes.

Changes

• Resync data/pc/26.1/proto.yml with master. On this branch 26.1 keeps its yaml in its own directory, and the master merges don't update that copy. It had fallen behind master's latest/proto.yml (Fix ClientboundEntityUpdateAttributes key mapper: missing attributes shift every subsequent attribute's name #1254, pc/26.1: map every InteractionHand field to main_hand/off_hand #1278, Fix PC protocol enum inconsistencies in difficulty, game-state reasons, and entity actions packet fields #1295), while 26.1/protocol.json already matched master, so the protocol.json is desynced from yaml test failed. This is master's yaml as is, and npm run build leaves protocol.json unchanged.
• The attribute mapper gets the five new 26.2 attributes. minecraft:attribute has 40 entries in 26.2. air_drag_modifier, below_name_distance, bounciness, friction_modifier and name_tag_distance are inserted in registry order. Without them, every entity_update_attributes key from id 0 on decoded as its neighbour (live, movement_speed arrived as explosion_knockback_resistance).
• sounds.json numbered from 0, from the 26.2 sound_event registry (same names, same order). node-minecraft-protocol turns the holder value into the registry id and mineflayer indexes registry.sounds by it, so 1-based ids resolved every registry sound to its neighbour. This is the fix pc: sound ids from the registry (0-based) and sounds for every 1.14+ version #1316 makes for 1.14 to 26.1.
• loginPacket.json regenerated from a vanilla 26.2 server, captured by node-minecraft-protocol's client test. The old file was 26.1's registries plus onlineMode. It lacked the new minecraft:sulfur_cube_archetype registry, the sulfur_cube_hot damage type and the bounce song, and it kept 26.1's enchantment predicates (what pc 26.2: fix enchantment entity predicates in loginPacket.json #1322 fixes by hand) and timeline values. I compared every entry with the jar's datapack JSON: the only differences are the fields vanilla does not sync to clients.
• Block and entity loot regenerated from the 26.2 jar, with minecraft-jar-extractor's extraction and prismarine-loottable master (which has Read the 1.14+ loot table formats: number providers, any_of, 1.21 predicates prismarine-loottable#15). The same run on the 26.1.2 jar reproduces pc: regenerate block and entity loot for 1.14.4 - 26.1 #1312's 26.1 files entry for entry. The old files were the 1.20 tables plus the new blocks, so they still named chain and grass. 26.2 adds the 28 sulfur and cinnabar blocks and the sulfur cube; no existing table changed.

Compared with #1339, I dropped the minecraft:color to minecraft:team_color command argument rename, following the updated naming guidance in copilot-instructions.md. The id is unchanged, so the old name still decodes correctly.

Testing

• npm test in tools/js: 3308 passing, 90 pending, 0 failing. On the current pc_26_2 without this PR, the sound ids, the 26.2 loot and the 26.1 yaml sync fail.
• Check against the jar: with this PR, every registry-backed mapper in 26.2/protocol.json lines up by id with the vanilla 26.2 registries.json. The names trial_spawner_detected_player, nbt, dyed_slot_demo and color differ from vanilla but are kept on purpose. Blocks (32366 states), items, entities, metadata, particles, sounds and attributes all match the reports.
• Downstream: the same data changes were tested in pc 26.2: merge master and fix the data checked against the 26.2 jar #1339. The node-minecraft-protocol and mineflayer 26.2 suites pass against vanilla 26.2 (26.2: merge master and drop the protodef debug overrides node-minecraft-protocol#1550, 26.2: merge master and drop the protodef debug overrides mineflayer#4192). A mineflayer bot on Paper and vanilla 26.2 servers passes 31 checks verified through RCON, plus the End, Nether and respawn checks.